The present invention relates in general to a plural platen clamping table assembly for securing workpieces on the table or platen of a metal working machine, and more particularly to a clamping table assembly having plural platens provided with patterns of tapped holes and reamed holes adapted to have securing bars or blocks fixed thereto and to be quick set by hydraulic actuating means to provide any size vise up to the maximum size of the table for securing regular and irregular shaped workpieces in a desired position on a metal working machine.
Heretofore, many types of removable workpiece supporting vise or fixture assemblies have been provided to provide a predetermined workpiece positioning assembly on a metal working machine. One of the traditional problems in such workpiece positioning assemblies has been the considerable amount of so-called "set-up" time to properly position the workpiece prior to each forming operation. This problem has been particularly acute where it is desired to provide the workpiece supporting assembly with sufficient flexibility to permit it to secure in proper position irregular shaped workpieces as well as regular shaped workpieces such as cubes, rectangular solids or cylinders. Also, such workpiece positioning tables or assemblies have frequently been quite limited in the variety of sizes of workpieces which can be accommodated.
An object of the present invention, therefore, is the provision of a novel multiple platen quick set hydraulic clamping table assembly for securing workpieces on a metal working machine or the like, having drilled and threaded platens arranged in at least one pair of platens which can be hydraulically moved toward and away from each other, each providing a large rectangular area providing a wide variety of positions for mounting securing bars or blocks thereon to provide a workpiece holding vise accommodating workpieces up to the maximum size of the table. Another object of the present invention is the provision of multiple platen hydraulically actuated clamping table assembly of the type described in the preceding paragraph, wherein the securing bars or blocks may be secured in such positions that irregular shaped workpieces may be easily secured thereon.
Another object of the present invention is the provision of a novel multiple platen clamping table assembly of the type described in either of the preceding paragraphs, having a centralizing device for each relatively movable correlated pair of platens, whereby the centralizing device may be selectively engaged to effect securing of round or symmetrical workpieces with reference to their centerline, either by engagement of the outside surfaces or the inside surfaces, in the case of hollow workpieces.
Yet another object of the present invention is the provision of a novel multiple platen clamping table assembly as described in any of the preceding paragraphs, having means for locking the platens in position to enable the clamping table to be used as a an ordinary grid plate for the use of vertical clamping devices.
The clamping table assembly generally comprises a left-hand pair of drilled and threaded platens and a right-hand pair of drilled and threaded platens each tapped to receive mounting screws for supporting upright abutment bars or blocks to engage the periphery of the workpiece and secure it on the clamping table. The first or left-hand pair and second or right-hand pair of relatively movable platens are secured to slides for movement toward and away from each other, and include a centralizing device formed of semicircular bearing segments which bear upon cylindrically concave surfaces of bearing blocks and retainer blocks to coordinate approaching movement of the platens of a selected pair toward each other so that round or symmetrical pieces may be secured with reference to their centerline. Hydraulic drive means are provided arranged so that when hydraulic pressure is applied to one port, the two platens of a selected pair will be moved apart and when pressure is applied at another port they will move together in coordinating relation. In practice, a workpiece to be supported on the clamping table is placed on the platens so that it overlaps each one of at least a pair, or if necessary each one of both pairs, whereupon the abutment bars or blocks forming jaw pieces are secured to each platen, using shims with the jaws in open position interposed between the jaws and the workpiece to provide clearance when the jaws are open. When the shims are removed, the workpiece is then clamped by application of hydraulic pressure by a suitable manually operated valve to the appropriate port to move the two platens of a pair or the four platens, as the case may be, toward each other to effect quick clamping of the workpiece in proper position. Alternatively, when it may be suitable to merely have the rear platen move forwardly without movement of the front platen toward the rear, means are provided for adjusting the centralizing mechanism to allow movement of the bearings without transfer of force which would coordinate the movement of the two platens relative to each other, and hydraulic controls are operated to supply hydraulic pressure to the rear platen only.
Other objects, advantages and capabilities of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings illustrating a preferred embodiment of the invention.